Sound producing cell

ABSTRACT

A sound producing cell includes a membrane and an actuating layer. The membrane includes a first membrane subpart and a second membrane subpart, wherein the first membrane subpart and the second membrane subpart are opposite to each other. The actuating layer is disposed on the first membrane subpart and the second membrane subpart. The first membrane subpart includes a first anchored edge which is fully or partially anchored, and edges of the first membrane subpart other than the first anchored edge are non-anchored. The second membrane subpart includes a second anchored edge which is fully or partially anchored, and edges of the second membrane subpart other than the second anchored edge are non-anchored.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 18/048,027, filed on Oct. 19, 2022, which is a division of U.S.application Ser. No. 17/720,333, filed on Apr. 14, 2022, which claimsthe benefit of U.S. Provisional Application No. 63/187,357, filed on May11, 2021. The contents of these applications are incorporated herein byreference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present application relates to a sound producing cell, and moreparticularly, to a sound producing cell having a high yield rate and/ora high performance.

2. Description of the Prior Art

Since micro sound producing devices, such as MEMS (Micro ElectroMechanical System) microspeakers, can be used in various electronicdevices due to their small size, the micro sound producing devices aredeveloped rapidly in recent years. For example, a MEMS microspeaker mayuse a thin film piezoelectric material as actuator and asilicon-containing layer as membrane which are formed by at least onesemiconductor process. In order to make the microspeaker more widelyused, industry is committed to designing the microspeaker with the highyield rate and the high performance.

SUMMARY OF THE INVENTION

It is therefore a primary objective of the present invention to providea sound producing cell having a specific slit design and/or a specificrecess design to enhance the yield rate and the performance.

An embodiment of the present invention provides a sound producing cellincluding a membrane and an actuating layer. The membrane includes afirst membrane subpart and a second membrane subpart, wherein the firstmembrane subpart and the second membrane subpart are opposite to eachother. The actuating layer is disposed on the first membrane subpart andthe second membrane subpart. The first membrane subpart includes a firstanchored edge which is fully or partially anchored, and edges of thefirst membrane subpart other than the first anchored edge arenon-anchored. The second membrane subpart includes a second anchorededge which is fully or partially anchored, and edges of the secondmembrane subpart other than the second anchored edge are non-anchored.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a top view illustrating a soundproducing cell according to a first embodiment of the present invention.

FIG. 2 is an enlarging schematic diagram showing a structure in a regionR1 in FIG. 1 .

FIG. 3 to FIG. 8 are schematic diagrams illustrating structures atdifferent stages of a manufacturing method of a sound producing cellaccording to an embodiment of the present invention.

FIG. 9 is a schematic diagram of a top view illustrating a soundproducing cell according to a second embodiment of the presentinvention.

FIG. 10 is an enlarging schematic diagram showing a structure in aregion R2 in FIG. 9 .

FIG. 11 is a schematic diagram of a top view illustrating a soundproducing cell according to a third embodiment of the present invention.

FIG. 12 is a schematic diagram of a top view illustrating a soundproducing cell according to a fourth embodiment of the presentinvention.

FIG. 13 is a schematic diagram of a top view illustrating a soundproducing cell according to a fifth embodiment of the present invention.

FIG. 14 is a schematic diagram of a top view illustrating a soundproducing cell according to a sixth embodiment of the present invention.

FIG. 15 is an enlarging schematic diagram showing a structure in aregion R3 in FIG. 14 .

FIG. 16 is a schematic diagram of a top view illustrating a soundproducing cell according to a seventh embodiment of the presentinvention.

FIG. 17 is a schematic diagram of a top view illustrating a soundproducing cell according to an eighth embodiment of the presentinvention.

FIG. 18 is a schematic diagram of a top view illustrating a soundproducing cell according to a ninth embodiment of the present invention.

FIG. 19 is a schematic diagram of a side view illustrating the soundproducing cell according to the ninth embodiment of the presentinvention.

FIG. 20 is a schematic diagram of a top view illustrating a soundproducing cell according to a tenth embodiment of the present invention.

DETAILED DESCRIPTION

To provide a better understanding of the present invention to thoseskilled in the art, preferred embodiments and typical material or rangeparameters for key components will be detailed in the followdescription. These preferred embodiments of the present invention areillustrated in the accompanying drawings with numbered elements toelaborate on the contents and effects to be achieved. It should be notedthat the drawings are simplified schematics, and the material andparameter ranges of key components are illustrative based on the presentday technology, and therefore show only the components and combinationsassociated with the present invention, so as to provide a clearerdescription for the basic structure, implementing or operation method ofthe present invention. The components would be more complex in realityand the ranges of parameters or material used may evolve as technologyprogresses in the future. In addition, for ease of explanation, thecomponents shown in the drawings may not represent their actual number,shape, and dimensions; details may be adjusted according to designrequirements.

In the following description and in the claims, the terms “include”,“comprise” and “have” are used in an open-ended fashion, and thus shouldbe interpreted to mean “include, but not limited to . . . ”. Thus, whenthe terms “include”, “comprise” and/or “have” are used in thedescription of the present invention, the corresponding features, areas,steps, operations and/or components would be pointed to existence, butnot limited to the existence of one or a plurality of the correspondingfeatures, areas, steps, operations and/or components.

In the following description and in the claims, when “a B1 component isformed by/of C1”, C1 exist in the formation of B1 component or C1 isused in the formation of B1 component, and the existence and use of oneor a plurality of other features, areas, steps, operations and/orcomponents are not excluded in the formation of B1 component.

In the following, the term “horizontal direction” generally means adirection parallel to a horizontal plane, the term “horizontal plane”generally means a plane parallel to a direction X and direction Y in thedrawings, and the term “vertical direction” generally means a directionparallel to a direction Z in the drawings, wherein the directions X, Yand Z are perpendicular to each other. In the following, the term “topview” generally means a viewing result along the vertical direction, andthe term “side view” generally means a viewing result along thehorizontal direction.

In the following description and in the claims, the term “substantially”generally means a small deviation may exist or not exist. For instance,the terms “substantially parallel” and “substantially along” means thatan angle between two components may be less than or equal to a certaindegree threshold, e.g., 10 degrees, 5 degrees, 3 degrees or 1 degree.For instance, the term “substantially aligned” means that a deviationbetween two components may be less than or equal to a certain differencethreshold, e.g., 2 μm or 1 μm. For instance, the term “substantially thesame” means that a deviation is within, e.g., 10% of a given value orrange, or mean within 5%, 3%, 2%, 1%, or 0.5% of a given value or range.

Although terms such as first, second, third, etc., may be used todescribe diverse constituent elements, such constituent elements are notlimited by the terms. The terms are used only to discriminate aconstituent element from other constituent elements in thespecification, and the terms do not relate to the sequence of themanufacture if the specification do not describe. The claims may not usethe same terms, but instead may use the terms first, second, third, etc.with respect to the order in which an element is claimed. Accordingly,in the following description, a first constituent element may be asecond constituent element in a claim.

It should be noted that the technical features in different embodimentsdescribed in the following can be replaced, recombined, or mixed withone another to constitute another embodiment without departing from thespirit of the present invention.

In the present invention, the sound producing cell may perform anacoustic transformation converting signals (e.g. electric signals orsignals with other suitable type) into an acoustic wave. In someembodiments, the sound producing cell may be a component in a soundproducing device, a speaker, a microspeaker or other suitable device, soas to convert the electric signals into the acoustic wave, but notlimited thereto. Note that an operation of the sound producing cellmeans that the acoustic transformation is performed by the soundproducing cell (e.g., the acoustic wave is produced by actuating thesound producing cell with electrical driving signal).

In the use of the sound producing cell, the sound producing cell may bedisposed on a base. The base may be hard or flexible, wherein the basemay include silicon, germanium, glass, plastic, quartz, sapphire, metal,polymer (e.g., polyimide (PI), polyethylene terephthalate (PET)), anyother suitable material or a combination thereof. As an example, thebase may be a circuit board including a laminate (e.g. copper cladlaminate, CCL), a land grid array (LGA) board or any other suitableboard containing conductive material, but not limited thereto. Note thata normal direction of the base may be parallel to the direction Z in thedrawings.

Referring to FIG. 1 and FIG. 2 , FIG. 1 is a schematic diagram of a topview illustrating a sound producing cell according to a first embodimentof the present invention, and FIG. 2 is an enlarging schematic diagramshowing a structure in a region R1 in FIG. 1 . As shown in FIG. 1 , thesound producing cell 100 includes a membrane 110 and at least one anchorstructure 120 outside the membrane 110, wherein the membrane 110 isconnected to the anchor structure 120, so as to be anchored by theanchor structure 120. For example, the membrane 110 may be surrounded bythe anchor structure 120, but not limited thereto.

In the operation of the sound producing cell 100, the membrane 110 canbe actuated to have a movement. In this embodiment, the membrane 110 maybe actuated to move upwardly and downwardly, but not limited thereto.Note that, in the present invention, the terms “move upwardly” and “movedownwardly” represent that the membrane 110 moves substantially alongthe direction Z. During the operation of the sound producing cell 100,the anchor structure 120 may be immobilized. Namely, the anchorstructure 120 may be a fixed end (or fixed edge) respecting the membrane110 during the operation of the sound producing cell 100.

A shape of the membrane 110 may be designed based on requirement(s). Insome embodiments, the shape of the membrane 110 may be a polygon (i.e.,a rectangle or a rectangle with chamfers), a shape having a curved edgeor other suitable shapes, but not limited thereto. For example, theshape of the membrane 110 shown in FIG. 1 may be a rectangle withchamfers, but not limited thereto.

The membrane 110 and the anchor structure 120 may include any suitablematerial(s). In some embodiments, the membrane 110 and the anchorstructure 120 may individually include silicon (e.g., single crystallinesilicon or poly-crystalline silicon), silicon compound (e.g., siliconcarbide, silicon oxide), germanium, germanium compound (e.g., galliumnitride or gallium arsenide), gallium, gallium compound or a combinationthereof, but not limited thereto. The membrane 110 and the anchorstructure 120 may have the same material or different materials.

In the present invention, the membrane 110 may include a plurality ofsubparts. As shown in FIG. 1 , the membrane 110 includes a firstmembrane subpart 112 and a second membrane subpart 114, wherein thefirst membrane subpart 112 and the second membrane subpart 114 areopposite to each other in the top view, only one edge of the firstmembrane subpart 112 is anchored by being connected to the anchorstructure 120, only one edge of the second membrane subpart 114 isanchored by being connected to the anchor structure 120, and other edgesof the first membrane subpart 112 and other edges of the second membranesubpart 114 are non-anchored and not connected to the anchor structure120 (these edges are referred as “non-anchored edges” in the following).Namely, in FIG. 1 , a first anchored edge 112 a of the first membranesubpart 112 is an only one edge of the first membrane subpart 112 whichis anchored, and a second anchored edge 114 a of the second membranesubpart 114 is an only one edge of the second membrane subpart 114 whichis anchored, wherein the first membrane subpart 112 is directlyconnected to the anchor structure 120 through the first anchored edge112 a only, and the second membrane subpart 114 is directly connected tothe anchor structure 120 through the second anchored edge 114 a only. Inthe present invention, the first anchored edge 112 a and the secondanchored edge 114 a may be fully or partially anchored. For example, inthe embodiment shown in FIG. 1 , the first anchored edge 112 a and thesecond anchored edge 114 a are fully anchored.

As shown in FIG. 1 , the membrane 110 has a plurality of slits SL,wherein the membrane 110 may be divided into the subparts by the slit(s)SL. In the present invention, the slit SL may have at least one straightpattern, at least one curved pattern or a combination thereof, and awidth of the slit SL should be sufficiently small. For example, thewidth of the slit SL may range from 1 μm to 5 μm, but not limitedthereto.

In FIG. 1 and FIG. 2 , the membrane 110 may have a first slit SL1, atleast one second slit SL2 and at least one third slit SL3, wherein thefirst slit SL1 may be formed between the first membrane subpart 112 andthe second membrane subpart 114, the second slit SL2 may be formedbetween the first membrane subpart 112 and the anchor structure 120, thethird slit SL3 may be formed between the second membrane subpart 114 andthe anchor structure 120, an end of the second slit SL2 may be situatedin a corner region CR (shown in FIG. 2 ) of the membrane 110, and an endof the third slit SL3 may be situated in another corner region CR of themembrane 110. For example, in FIG. 1 , the membrane 110 may have onefirst slit SL1, two second slits SL2 and two third slits SL3 which arestraight, the first membrane subpart 112 may be between two second slitsSL2 in the top view, and the second membrane subpart 114 may be betweentwo third slits SL3 in the top view, but not limited thereto.

In FIG. 1 , the non-anchored edges of each subpart may be accomplishedby the slits SL. Regarding the first membrane subpart 112, a firstnon-anchored edge 112 n 1 opposite to the first anchored edge 112 a inthe top view may be defined by the first slit SL1, and a secondnon-anchored edge 112 n 2 adjacent to the first anchored edge 112 a isdefined by the second slit SL2. Regarding the second membrane subpart114, a third non-anchored edge 114 n 3 opposite to the second anchorededge 114 a in the top view may be defined by the first slit SL1, and afourth non-anchored edge 114 n 4 adjacent to the second anchored edge114 a is defined by the third slit SL3.

In the present invention, shapes of the subparts of the membrane 110 maybe designed based on requirement(s), wherein the shape of the subpart ofthe membrane 110 of may be a polygon (i.e., a rectangle), a shape havinga curved edge or other suitable shapes. For instance, in FIG. 1 , theshape of the first membrane subpart 112 and the shape of the secondmembrane subpart 114 may substantially be rectangles, and the firstmembrane subpart 112 and the second membrane subpart 114 may besubstantially congruent, but not limited thereto. Thus, in FIG. 1 , thesecond non-anchored edge 112 n 2 may be adjacent to and between thefirst non-anchored edge 112 n 1 and the first anchored edge 112 a, andthe fourth non-anchored edge 114 n 4 may be adjacent to and between thethird non-anchored edge 114 n 3 and the second anchored edge 114 a, butnot limited thereto. In FIG. 1 , the second slit SL2 and the third slitSL3 are connected to the first slit SL1. For example, the first slit SL1may be connected between two second slits SL2 and connected between twothird slits SL3, but not limited thereto.

Since the shape of the first membrane subpart 112 and the shape of thesecond membrane subpart 114 may substantially be rectangles, the firstanchored edge 112 a, the first non-anchored edge 112 n 1, the secondanchored edge 114 a and the third non-anchored edge 114 n 3 aresubstantially parallel to each other and have substantially the samelength, and the second non-anchored edges 112 n 2 and the fourthnon-anchored edges 114 n 4 are substantially parallel to each other(i.e., parallel to the direction X) and have substantially the samelength. That is to say, the first slit SL1 defining the firstnon-anchored edge 112 n 1 and the third non-anchored edge 114 n 3 isparallel to the first anchored edge 112 a and the second anchored edge114 a.

In some embodiments, in FIG. 1 , the second slit SL2 and the third slitSL3 may be connected, such that the second slit SL2 and the third slitSL3 may be combined to form a long straight slit, but not limitedthereto.

As shown in FIG. 1 , the first anchored edge 112 a of the first membranesubpart 112 is one of the edges of the membrane 110, and the secondanchored edge 114 a of the second membrane subpart 114 is another one ofthe edges of the membrane 110. The second non-anchored edge 112 n 2 ofthe first membrane subpart 112 may be or may not be one of the edges ofthe membrane 110, and the fourth non-anchored edge 114 n 4 of the secondmembrane subpart 114 may be or may not be one of the edges of themembrane 110. For example, in FIG. 1 , the second non-anchored edge 112n 2 of the first membrane subpart 112 may not be the edge of themembrane 110, and the fourth non-anchored edge 114 n 4 of the secondmembrane subpart 114 may not be the edge of the membrane 110, such thatthe second slit SL2 may be between the first membrane subpart 112 andone of the edges of the membrane 110 in the top view, and the third slitSL3 may be between the second membrane subpart 114 and one of the edgesof the membrane 110 in the top view, but not limited thereto.

Note that the slit SL may release the residual stress of the membrane110, wherein the residual stress is generated during the manufacturingprocess of the membrane 110 or originally exist in the membrane 110.

The sound producing cell 100 may include an actuating layer 130 disposedon the membrane 110 and configured to actuate the membrane 110. In someembodiments, as shown in FIG. 1 , the actuating layer 130 may nottotally overlap the membrane 110 in the top view. For example, in FIG. 1, the actuating layer 130 may be disposed on the first membrane subpart112 and the second membrane subpart 114, and the actuating layer 130 mayoverlap a portion of the first membrane subpart 112 and a portion of thesecond membrane subpart 114 in the top view. Optionally, in FIG. 1 , theactuating layer 130 may be disposed on and overlap the anchor structure120, and the actuating layer 130 may overlap the anchored edge of thesubpart of the membrane 110, but not limited thereto.

As shown in FIG. 1 , in the top view, a distance may exist between theactuating layer 130 and the slit SL, so as to enhance the reliability ofthe slit SL and the actuating layer 130, but not limited thereto.

The actuating layer 130 may include an actuator having a monotonicelectromechanical converting function with respect to the movement ofmembrane 110 along the direction Z. In some embodiments, the actuatinglayer 130 may include a piezoelectric actuator, an electrostaticactuator, a nanoscopic-electrostatic-drive (NED) actuator, anelectromagnetic actuator or any other suitable actuator, but not limitedthereto. For example, in an embodiment, the actuating layer 130 mayinclude a piezoelectric actuator, the piezoelectric actuator may containsuch as two electrodes and a piezoelectric material layer (e.g., leadzirconate titanate, PZT) disposed between the electrodes, wherein thepiezoelectric material layer may actuate the membrane 110 based ondriving signals (e.g., driving voltages) received by the electrodes, butnot limited thereto. For example, in another embodiment, the actuatinglayer 130 may include an electromagnetic actuator (such as a planarcoil), wherein the electromagnetic actuator may actuate the membrane 110based on a received driving signals (e.g., driving current) and amagnetic field (i.e. the membrane 110 may be actuated by theelectromagnetic force), but not limited thereto. For example, in stillanother embodiment, the actuating layer 130 may include an electrostaticactuator (such as conducting plate) or a NED actuator, wherein theelectrostatic actuator or the NED actuator may actuate the membrane 110based on a received driving signals (e.g., driving voltage) and anelectrostatic field (i.e. the membrane 110 may be actuated by theelectrostatic force), but not limited thereto.

The membrane 110 is actuated by the actuating layer 130, so as to movealong the direction Z, thereby performing the acoustic transformation.Namely, the subpart of the membrane 110 may be actuated to perform anup-and-down movement, such that the acoustic transformation isperformed. Note that, the acoustic wave is produced due to the movementof the membrane 110 actuated by the actuating layer 130, and themovement of the membrane 110 is related to a sound pressure level (SPL)of the acoustic wave.

When the subpart performs the up-and-down movement, openings in thedirection Z may be formed and adjacent to its all non-anchored edges.For example, in the operation of the sound producing cell 100, a centralopening may be formed between the first non-anchored edge 112 n 1 of thefirst membrane subpart 112 and the third non-anchored edge 114 n 3 ofthe second membrane subpart 114, and side openings may be respectivelyformed between the second non-anchored edge 112 n 2 of the firstmembrane subpart 112 and the anchor structure 120 and between the fourthnon-anchored edge 114 n 4 of the second membrane subpart 114 and theanchor structure 120.

The subparts of the membrane 110 move along the same direction oropposite directions based on requirement(s). In some embodiments, thefirst membrane subpart 112 and the second membrane subpart 114 may moveup and down in the direction Z synchronously (i.e., the first membranesubpart 112 and the second membrane subpart 114 may be actuated to movetoward the same direction) to avoid big central opening between thefirst membrane subpart 112 and the second membrane subpart 114 frombeing formed, but not limited thereto.

The actuating layer 130 may actuate the membrane 110 to produce theacoustic wave based on received driving signal(s). The acoustic wave iscorresponding to an input audio signal, and the driving signal appliedon the actuating layer 130 is corresponding to (related to) the inputaudio signal.

Note that, the short side of the sound producing cell 100 (or membrane110) may be beneficial for obtaining higher resonant frequency, and thelong side of the sound producing cell 100 (or membrane 110) may bebeneficial for enlarging SPL. In other words, the sound producing cell100 (or membrane 110) with large aspect ratio, a ratio of a length ofthe long side thereof with respect to a length of the short side, mayachieve both higher resonant frequency and the larger SPL, compared to acell with less aspect ratio. The aspect ratio for the sound producingcell 100 (or membrane 110) may depend on practical requirement. Forexample, the aspect ratio of the sound producing cell 100 (or membrane110) may be larger than 2, so as to enhance the performance of the soundproducing cell 100, but not limited thereto.

In the following, the details of a method of manufacturing a soundproducing cell 100 will be further exemplarily explained. Note that inthe following manufacturing method, the actuating layer 130 in the soundproducing cell 100 may include a piezoelectric actuator for example, butnot limited thereto. Any suitable type actuator can be included in theactuating layer 130 of the sound producing cell 100.

In the following manufacturing method, the forming process may includeatomic layer deposition (ALD), a chemical vapor deposition (CVD) andother suitable process(es) or a combination thereof. The patterningprocess may include such as a photolithography, an etching process, anyother suitable process(es) or a combination thereof.

Referring to FIG. 3 to FIG. 8 , FIG. 3 to FIG. 8 are schematic diagramsillustrating structures at different stages of a manufacturing method ofa sound producing cell according to an embodiment of the presentinvention. In this embodiment, the sound producing cell 100 may bemanufactured by at least one semiconductor process to be a MEMS chip,but not limited thereto. As shown in FIG. 3 , a wafer WF is provided,wherein the wafer WF may include a first layer WL1 and a second layerWL2, and may optionally include an insulating layer WL3 between thefirst layer WL1 and the second layer WL2.

The first layer WL1, the insulating layer WL3 and the second layer WL2may individually include any suitable material, such that the wafer WFmay be any suitable type. For instance, the first layer WL1 and thesecond layer WL2 may individually include silicon (e.g., singlecrystalline silicon or poly-crystalline silicon), silicon carbide,germanium, gallium nitride, gallium arsenide, other suitable material ora combination thereof. In some embodiments, the first layer WL1 mayinclude single crystalline silicon, such that the wafer WF may be asilicon on insulator (SOI) wafer, but not limited thereto. For instance,the insulating layer WL3 may include oxide, such as silicon oxide (e.g.,silicon dioxide), but not limited thereto. The thicknesses of the firstlayer WL1, the insulating layer WL3 and the second layer WL2 may beindividually adjusted based on requirement(s).

In FIG. 3 , a compensation oxide layer CPS may be optionally formed onan upper side of the wafer WF, wherein the upper side is upper than atop surface WL1 a of the first layer WL1 opposite to the second layerWL2, such that the first layer WL1 is between the compensation oxidelayer CPS and the second layer WL2. The material of oxide contained inthe compensation oxide layer CPS and the thickness of the compensationoxide layer CPS may be designed based on requirement(s).

In FIG. 3 , a first conductive layer CT1 and an actuating material AMmay be formed on the upper side of the wafer WF (on the first layer WL1)in sequence, such that the first conductive layer CT1 may be between theactuating material AM and the first layer WL1. In some embodiments, thefirst conductive layer CT1 may be in contact with the actuating materialAM.

The first conductive layer CT1 may include any suitable conductivematerial, and the actuating material AM may include any suitablematerial. In some embodiments, the first conductive layer CT1 mayinclude metal (such as platinum), and the actuating material AM mayinclude a piezoelectric material, but not limited thereto. For example,the piezoelectric material may include such as a lead-zirconate-titanate(PZT) material, but not limited thereto. Moreover, the thicknesses ofthe first conductive layer CT1 and the actuating material AM may beindividually adjusted based on requirement(s).

Then, in FIG. 3 , the actuating material AM, the first conductive layerCT1 and the compensation oxide layer CPS may be patterned in sequence.

As shown in FIG. 4 , a separating insulating layer SIL may be formed onthe actuating material AM and be patterned. The thickness of theseparating insulating layer SIL and the material of the separatinginsulating layer SIL may be designed based on requirement(s). Forinstance, the material of the separating insulating layer SIL may beoxide, but not limited thereto.

As shown in FIG. 4 , a second conductive layer CT2 may be formed on theactuating material AM and the separating insulating layer SIL, and then,the second conductive layer CT2 may be patterned. The thickness of thesecond conductive layer CT2 and the material of the second conductivelayer CT2 may be designed based on requirement(s). For instance, thesecond conductive layer CT2 may include metal (such as platinum), butnot limited thereto. For instance, the second conductive layer CT2 maybe in contact with the actuating material AM.

The actuating material AM, the first conductive layer CT1 and the secondconductive layer CT2 may be sub-layers in the actuating layer 130 of thesound producing cell 100, so as to make the actuating layer 130 have apiezoelectric actuator including two electrodes and the actuatingmaterial AM between two electrodes.

In FIG. 4 , the separating insulating layer SIL may be configured toseparate at least a portion of the first conductive layer CT1 from atleast a portion of the second conductive layer CT2.

As shown in FIG. 5 , the first layer WL1 of the wafer WF may bepatterned, so as to form a trench line TL. In FIG. 5 , the trench lineTL is a portion where the first layer WL1 is removed. That is to say,the trench line TL is between two parts of the first layer WL1.

As shown in FIG. 6 , the wafer WF is disposed on a substrate SB and anadhering layer AL, wherein the adhering layer AL is adhered between thesubstrate SB and the first layer WL1 of the wafer WF. In FIG. 6 , theactuating layer 130 is between the wafer WF and the substrate SB. Due tothis step, the first layer WL1 of the wafer WF and the structures on theupper side of the wafer WF (i.e., the structures upper than the topsurface WL1 a of the wafer WF) may be protected in subsequent steps.

As shown in FIG. 7 , the second layer WL2 of the wafer WF may bepatterned, so as to make the second layer WL2 form the anchor structure120 and to make the first layer WL1 form the membrane 110 anchored bythe anchor structure 120. In detail, the second layer WL2 of the waferWF may have a first part and a second part, the first part of the secondlayer WL2 may be removed, and the second part of the second layer WL2may form the anchor structure 120. Since the first part of the secondlayer WL2 is removed, the first layer WL1 forms the membrane 110,wherein the membrane 110 is corresponding to the removing first part ofthe second layer WL2 in the top view. For example, the first part of thesecond layer WL2 may be removed by a deep reactive ion etching (DRIE)process, but not limited thereto. Note that the subparts (e.g., thefirst membrane subpart 112 and the second membrane subpart 114) of themembrane 110 are determined when patterning the first layer WL1 of thewafer WF to form the trench line(s) TL.

Optionally, in FIG. 7 , since the insulating layer WL3 of the wafer WFexists, after the second layer WL2 of the wafer WF is patterned, a partof the insulating layer WL3 corresponding to the first part of thesecond layer WL2 may be removed also, so as to make the first layer WL1form the membrane 110, but not limited thereto.

Furthermore, in FIG. 7 , the second part of the second layer WL2, aportion of the insulating layer WL3 overlapping the second part of thesecond layer WL2 and a portion of the first layer WL1 overlapping thesecond part of the second layer WL2 may be combined to serve as theanchor structure 120.

As shown in FIG. 8 , the substrate SB and the adhering layer AL areremoved by a suitable process, so as to complete the manufacture of thesound producing cell 100. For example, the substrate SB and the adheringlayer AL may be removed by a peel-off process, but not limited thereto.

In FIG. 8 , since the first part of the second layer WL2 is removed tomake the membrane 110 included in the first layer WL1 be formed, theslit SL is formed within and penetrates through the membrane 110 becauseof the trench line TL. Since the slit SL is formed because of the trenchline TL, the width of the trench line TL may be designed based on therequirement of the slit SL. For example, the width of the trench line TLmay be less than or equal to 5 μm, less than or equal to 3 μm, or lessthan or equal to 2 μm, so as to make the slit SL have desire width, butnot limited thereto.

The sound producing cell and its manufacturing method of the presentinvention are not limited by the above embodiments. Other embodiments ofthe present invention are described below. For ease of comparison, samecomponents will be labeled with the same symbol in the following. Thefollowing descriptions relate the differences between each of theembodiments, and repeated parts will not be redundantly described.

Referring to FIG. 9 and FIG. 10 , FIG. 9 is a schematic diagram of a topview illustrating a sound producing cell according to a secondembodiment of the present invention, and FIG. 10 is an enlargingschematic diagram showing a structure in a region R2 in FIG. 9 . Asshown in FIG. 9 and FIG. 10 , a difference between this embodiment andthe first embodiment is that the sound producing cell 200 of thisembodiment includes a recess structure RS disposed at a corner of thesound producing cell 200 and outside the membrane 110, wherein therecess structure RS is directly connected to a slit segment SLs in thecorner region CR of the membrane 110. In the embodiment shown in FIG. 9, the sound producing cell 200 may include four recess structures RSdisposed at four corners of the sound producing cell 200 and outside themembrane 110, but not limited thereto.

The slit segment SLs in the corner region CR may be a slit SL connectedto the second slit SL2 or the third slit SL3, or the slit segment SLs inthe corner region CR may be a portion of the second slit SL2 or aportion of the third slit SL3. The slit segment SLs may have a curvedpattern, a straight pattern or a combination thereof. For example, inFIG. 10 , the slit segment SLs may be connected between the end of thesecond slit SL2 situated in the corner region CR and the recessstructure RS, and the slit segment SLs may have a curved pattern, butnot limited thereto.

As shown in FIG. 9 and FIG. 10 , the recess structure RS may be formedon the anchor structure 120 and at a corner of the sound producing cell200. For example, the sound producing cell 200 may have a first layerWL1 and a second layer WL2 disposed under the first layer WL1 (e.g.,FIG. 8 ), wherein a portion of the first layer WL1 may be configured toserve as the membrane 110 (i.e., the first layer WL1 may include themembrane 110), another portion of the first layer WL1 may surround themembrane 110 and combine with the second layer WL2 to be the anchorstructure 120, the slit segment SLs in the corner region CR of themembrane 110 may pass through the first layer WL1, and the recessstructure RS may pass through the first layer WL1 and have a bottombelonging to the anchor structure 120 (e.g., the second layer WL2), butnot limited thereto. In this case, regarding the manufacturing method ofthe sound producing cell 200, the slits SL of the membrane 110 and therecess structure RS may be patterned (etched) in the same process (thesame etching process).

As shown in FIG. 9 and FIG. 10 , the recess structure RS may have acurved pattern, and the curved pattern of the recess structure RS may bedesigned based on requirement(s). For instance, in FIG. 10 , the slitsegment SLs in the corner region CR and the recess structure RS may becombined to form a pattern with a half circular arc, but not limitedthereto.

The existence of the curved recess structure RS connected to the slitsegment SLs situating in the corner region CR may enhance the successrate of the manufacturing process of the sound producing cell 200,thereby increasing the yield rate of the sound producing cell 200. Indetail, in the step of removing the substrate SB and the adhering layerAL (e.g., the peel-off process), due to the existence of the curvedrecess structure RS connected to the slit segment SLs situating in thecorner region CR, the stress concentration position may be changed fromthe corner region CR of the membrane 110 (e.g., the end of the slit SL)to the recess structure RS, and the stress applied on the recessstructure RS may be dispersed, so as to reduce the damage on themembrane 110 during this process. Moreover, since the recess structureRS has the curved pattern, the stress applied on the recess structure RSin this process may be dispersed effectively, so as to decrease thedamage on the recess structure RS, thereby enhancing the success rate ofthe manufacturing process of the sound producing cell 200.

Referring to FIG. 11 , FIG. 11 is a schematic diagram of a top viewillustrating a sound producing cell according to a third embodiment ofthe present invention. As shown in FIG. 11 , a difference between thisembodiment and the first embodiment is that the membrane 110 of thesound producing cell 300 of this embodiment includes a latch structure310. Under the condition that the first membrane subpart 112 and thesecond membrane subpart 114 moves along the direction Z (i.e., thenormal direction of the base where the membrane 110 is disposed), thelatch structure 310 may lock the first membrane subpart 112 and thesecond membrane subpart 114 when a moving distance of the first membranesubpart 112 along the direction Z and a moving distance of the secondmembrane subpart 114 along the direction Z are greater than a thresholdvalue. Namely, the latch structure 310 is configured to limit movingdistances of the first membrane subpart 112 and the second membranesubpart 114.

Because the subpart of the membrane 110 only has one anchored edge, thesubpart of the membrane 110 may be fragile and may be damaged in themanufacturing process. In this embodiment, the existence of the latchstructure 310 may enhance the success rate of manufacturing the membrane110, thereby increasing the yield rate of the sound producing cell 300.In detail, in the step of removing the substrate SB and the adheringlayer AL (e.g., the peel-off process), the displacement of the firstmembrane subpart 112 and the displacement of the second membrane subpart114 along the direction Z are caused by the adhering force of theadhering layer AL. In this case, the latch structure 310 may lock thefirst membrane subpart 112 and the second membrane subpart 114 when thefirst membrane subpart 112 and the second membrane subpart 114 movealong the direction Z with a displacement greater than the thresholdvalue, so as to limit the movement of the first membrane subpart 112 andthe second membrane subpart 114 and provide a restoring force for thefirst membrane subpart 112 and the second membrane subpart 114, therebyreducing the damage on the membrane 110.

The latch structure 310 may have any suitable design based onrequirement(s). In this embodiment, the latch structure 310 shown inFIG. 11 may be formed because of the slit(s) SL. For example, in FIG. 11, the latch structure 310 may be formed because of two first slits SL1and three fourth slits SL4 and SL4′, wherein the first slits SL1 and thefourth slits SL4 and SL4′ may be between the first membrane subpart 112and the second membrane subpart 114, and three fourth slits SL4 and SL4′may be connected between two first slits SL1. In FIG. 11 , the firstslits SL1 may be parallel to each other, but not limited thereto. InFIG. 11 , the fourth slit SL4′ extending along the direction X may beconnected between two fourth slits SL4 extending along the direction Y,and the fourth slit SL4 extending along the direction Y may be connectedbetween the fourth slits SL4′ extending along the direction X and thefirst slit SL1 extending along the direction X, but not limited thereto.

As shown in FIG. 11 , the latch structure 310 may include a first latchcomponent 312 and a second latch component 314, the first latchcomponent 312 may be a portion of the first membrane subpart 112(equivalently, the first latch component 312 may belong to the firstmembrane subpart 112), and the second latch component 314 may be aportion of the second membrane subpart 114 (equivalently, the secondlatch component 314 may belong to the second membrane subpart 114). InFIG. 11 , the first latch component 312 may be disposed between thesecond latch component 314 of the second membrane subpart 114 andanother portion of the second membrane subpart 114, and the second latchcomponent 314 may be disposed between the first latch component 312 ofthe first membrane subpart 112 and another portion of the first membranesubpart 112. For example, in FIG. 11 , a length direction of the firstlatch component 312 and a length direction of the second latch component314 may be substantially parallel to the direction X, but not limitedthereto.

When the first membrane subpart 112 and the second membrane subpart 114move along the direction Z with a displacement greater than thethreshold value, the first latch component 312 is buckled to the secondlatch component 314, so as to lock the first membrane subpart 112 andthe second membrane subpart 114. Note that the width of the slit SL andthe size of the latch component are related to the buckled effect of thelatch structure 310.

Referring to FIG. 12 , FIG. 12 is a schematic diagram of a top viewillustrating a sound producing cell according to a fourth embodiment ofthe present invention. As shown in FIG. 12 , a difference between thisembodiment and the first embodiment is that the membrane 110 of thesound producing cell 400 of this embodiment includes at least one springconnected between the subparts of membrane 110, wherein the number ofthe spring(s) may be designed based on requirement(s). In FIG. 12 , themembrane 110 may include a first spring SPR1 directly connected betweenthe first membrane subpart 112 and the second membrane subpart 114.

Because of the existence of the first spring SPR1, the success rate ofmanufacturing the membrane 110 may be enhanced, thereby increasing theyield rate of the sound producing cell 400. In detail, in the step ofremoving the substrate SB and the adhering layer AL, the displacement ofthe first membrane subpart 112 and the displacement of the secondmembrane subpart 114 along the direction Z are caused by the adheringforce of the adhering layer AL. When the first membrane subpart 112 andthe second membrane subpart 114 move along the direction Z with a largedisplacement, the first spring SPR1 may limit the movement of the firstmembrane subpart 112 and the second membrane subpart 114 and provide arestoring force for the first membrane subpart 112 and the secondmembrane subpart 114, thereby reducing the damage on the membrane 110.

The spring may have any suitable design based on requirement(s). Asshown in FIG. 12 , the first spring SPR1 may be formed because of theslit(s) SL. In this embodiment, the first spring SPR1 shown in FIG. 12may be formed because of two first slits SL1 and two fifth slits SL5,wherein the fifth slit SL5 may be connected to the first slit SL1, andthe fifth slit SL5 may have a curved pattern. For instance, the fifthslit SL5 may include a hook-shaped curved pattern, and one end of thefifth slit SL5 is not connected to another slit SL, but not limitedthereto. For instance, the first slits SL1 may be parallel to eachother, but not limited thereto.

When the membrane 110 moves, the stress caused by the deformation of themembrane 110 may applied on the spring. In FIG. 12 , because the fifthslit SL5 includes the curved pattern (i.e., the hook-shaped curvedpattern), the effect of the stress concentration may be reduced, suchthat the damage on the membrane 110 and the first spring SPR1 may bereduced, thereby increasing the yield rate of the sound producing cell400.

In addition, as shown in FIG. 12 , a connecting direction from the firstspring SPR1 to the first membrane subpart 112 may be different from aconnecting direction from the first spring SPR1 to the second membranesubpart 114. For example, in FIG. 12 , the connecting direction from thefirst spring SPR1 to the first membrane subpart 112 may be opposite tothe connecting direction from the first spring SPR1 to the secondmembrane subpart 114, but not limited thereto. For example, in FIG. 12 ,the first spring SPR1 may substantially be a 1-shape, but not limitedthereto.

Referring to FIG. 13 , FIG. 13 is a schematic diagram of a top viewillustrating a sound producing cell according to a fifth embodiment ofthe present invention. As shown in FIG. 13 , a difference between thisembodiment and the fourth embodiment is the design of the first springSPR1. In FIG. 13 , the first spring SPR1 of the membrane 110 of thesound producing cell 500 may be formed because of the two first slitsSL1, two fifth slits SL5 and a sixth slit SL6, wherein two fifth slitsSL5 may be connected to the same first slit SL1, the sixth slit SL6 maybe connected to another first slit SL1, the fifth slit SL5 may have twocurved pattern and one straight pattern, and the sixth slit SL6 may bebetween two fifth slits SL5 and have a curved pattern. For instance, thefifth slit SL5 may include a hook-shaped curved pattern, and one end ofthe fifth slit SL5 is not connected to another slit SL, but not limitedthereto.

In addition, in the first spring SPR1 shown in FIG. 13 , the connectingdirection from the first spring SPR1 to the first membrane subpart 112may be the same as the connecting direction from the first spring SPR1to the second membrane subpart 114, but not limited thereto. Forexample, in FIG. 13 , the first spring SPR1 may substantially be aU-shape, but not limited thereto. Due to this design, the size of thecentral opening between the first membrane subpart 112 and the secondmembrane subpart 114 may be decreased, so as to reduce the leakage ofthe air in the operation of the sound producing cell 500.

When the membrane 110 moves, the stress caused by the deformation of themembrane 110 may applied on the spring. In FIG. 13 , because of thedesign of the U-shape first spring SPR1 having curved slits SL, theeffect of the stress concentration may be reduced, such that the damageon the membrane 110 and the first spring SPR1 may be reduced, therebyincreasing the yield rate of the sound producing cell 500.

Referring to FIG. 14 and FIG. 15 , FIG. 14 is a schematic diagram of atop view illustrating a sound producing cell according to a sixthembodiment of the present invention, and FIG. 15 is an enlargingschematic diagram showing a structure in a region R3 in FIG. 14 . Asshown in FIG. 14 and FIG. 15 , a difference between this embodiment andthe first embodiment is that the membrane 110 of the sound producingcell 600 of this embodiment further includes a third membrane subpart116 and a fourth membrane subpart 118. The third membrane subpart 116and the fourth membrane subpart 118 may be disposed between the firstmembrane subpart 112 and the second membrane subpart 114 in the topview, and the third membrane subpart 116 and the fourth membrane subpart118 may be opposite to each other in the top view. In other words, thethird membrane subpart 116 may be disposed by a first side (e.g., leftside) of the sound producing cell 600 between the first membrane subpart112 and the second membrane subpart 114 in the top view, the fourthmembrane subpart 118 may be disposed by a second side (e.g., right side)of the sound producing cell 600 between the first membrane subpart 112and the second membrane subpart 114 in the top view, and the first sideand the second side of the sound producing cell 600 may be opposite toeach other in the top view.

In FIG. 14 , only one edge of the third membrane subpart 116 may beanchored by being connected to the anchor structure 120, only one edgeof the fourth membrane subpart 118 may be anchored by being connected tothe anchor structure 120, and other edges of the third membrane subpart116 and other edges of the fourth membrane subpart 118 may benon-anchored and not connected to the anchor structure 120. Namely, athird anchored edge 116 a of the third membrane subpart 116 may be anonly one edge of the third membrane subpart 116 which is anchored, and afourth anchored edge 118 a of the fourth membrane subpart 118 is an onlyone edge of the fourth membrane subpart 118 which is anchored, whereinthe third membrane subpart 116 may be directly connected to the anchorstructure 120 through the third anchored edge 116 a only, and the fourthmembrane subpart 118 may be directly connected to the anchor structure120 through the fourth anchored edge 118 a only.

In FIG. 14 , one second slit SL2 may be between the first membranesubpart 112 and the third membrane subpart 116 to define one secondnon-anchored edge 112 n 2 of the first membrane subpart 112 and onefifth non-anchored edge 116 n 5 of the third membrane subpart 116,another second slit SL2 may be between the first membrane subpart 112and the fourth membrane subpart 118 to define another secondnon-anchored edge 112 n 2 of the first membrane subpart 112 and onesixth non-anchored edge 118 n 6 of the fourth membrane subpart 118, onethird slit SL3 may be between the second membrane subpart 114 and thethird membrane subpart 116 to define one fourth non-anchored edge 114 n4 of the second membrane subpart 114 and another fifth non-anchored edge116 n 5 of the third membrane subpart 116, and another third slit SL3may be between the second membrane subpart 114 and the fourth membranesubpart 118 to define another fourth non-anchored edge 114 n 4 of thesecond membrane subpart 114 and another sixth non-anchored edge 118 n 6of the fourth membrane subpart 118. In some embodiments, the fifthnon-anchored edge 116 n 5 of the third membrane subpart 116 may beadjacent to the third anchored edge 116 a of the third membrane subpart116, and the sixth non-anchored edge 118 n 6 of the fourth membranesubpart 118 may be adjacent to the fourth anchored edge 118 a of thefourth membrane subpart 118, but not limited thereto.

As shown in FIG. 14 , the shape of the first membrane subpart 112 andthe shape of the second membrane subpart 114 may substantially betrapezoids, the shape of the third membrane subpart 116 and the shape ofthe fourth membrane subpart 118 may substantially be triangles, thefirst membrane subpart 112 and the second membrane subpart 114 may besubstantially congruent, and the third membrane subpart 116 and thefourth membrane subpart 118 may be substantially congruent, but notlimited thereto.

During the operation of the sound producing cell 600, side openings arerespectively between the first membrane subpart 112 and the thirdmembrane subpart 116, between the second membrane subpart 114 and thethird membrane subpart 116, between the first membrane subpart 112 andthe fourth membrane subpart 118 and between the second membrane subpart114 and the fourth membrane subpart 118. The size of the side opening isrelative to a low frequency roll-off (LFRO) effect in the frequencyresponse of the sound producing cell 600, wherein the strong LFRO effectmay cause an evident SPL drop of the acoustic wave in the low frequency.

In detail, regarding the side opening of the sound producing cell 600,an acoustic resistance for low frequency may be according to a formula:

${R \propto \frac{L}{b \times d^{3}}},$

wherein x is the acoustic resistance for low frequency, L is thethickness of the membrane 110, b is the length of the secondnon-anchored edge 112 n 2 of the first membrane subpart 112 or thelength of the fourth non-anchored edge 114 n 4 of the second membranesubpart 114, and d is the maximum size of the side opening in thedirection Z. If the acoustic resistance for low frequency is increased,the leakage of the air (e.g., acoustic leakage) in the operation of thesound producing cell 600 is decreased, so as to reduce the LFRO effectin the frequency response of the sound producing cell 600.

According to the formula, when d (i.e., the maximum size of the sideopening in the direction Z) is decreased, the acoustic resistance forlow frequency is increased. In the first embodiment shown in FIG. 1 ,regarding the first membrane subpart 112, the maximum size of the sideopening in the direction Z is a maximum distance between the secondnon-anchored edge 112 n 2 and the anchor structure 120 in the directionZ. In the sixth embodiment shown in FIG. 14 , regarding the firstmembrane subpart 112, the maximum size of the side opening in thedirection Z is a maximum distance between the second non-anchored edge112 n 2 of the first membrane subpart 112 and the fifth non-anchorededge 116 n 5 of the third membrane subpart 116 (or the sixthnon-anchored edge 118 n 6 of the fourth membrane subpart 118) in thedirection Z. In the sixth embodiment shown in FIG. 14 , since the thirdmembrane subpart 116 and the fourth membrane subpart 118 exist, d shownin the formula may be decreased by controlling the third membranesubpart 116 and the fourth membrane subpart 118 to be close to the firstmembrane subpart 112 and the second membrane subpart 114 in thedirection Z during the operation of the sound producing cell 600. Thatis to say, in FIG. 14 , the third membrane subpart 116 may be configuredto reduce the acoustic leakage at the first side (left side) of thesound producing cell 600, and the fourth membrane subpart 118 isconfigured to reduce the acoustic leakage at the second side (rightside) of the sound producing cell.

The sound producing cell 600 may include at least one suitable structureto make d (i.e., the maximum size of the side opening in the directionZ) decreased, thereby enhancing the acoustic resistance for lowfrequency. In this embodiment, due to this suitable structure, duringthe operation of the sound producing cell 600, the fifth non-anchorededges 116 n 5 of the third membrane subpart 116 may be respectivelyclose to the second non-anchored edge 112 n 2 of the first membranesubpart 112 and the fourth non-anchored edge 114 n 4 of the secondmembrane subpart 114 in the direction Z, and the sixth non-anchorededges 118 n 6 of the fourth membrane subpart 118 may be respectivelyclose to the second non-anchored edge 112 n 2 of the first membranesubpart 112 and the fourth non-anchored edge 114 n 4 of the secondmembrane subpart 114 in the direction Z. Accordingly, during theoperation of the sound producing cell 600, the sizes of the sideopenings may be reduced, so as to enhance the acoustic resistance forlow frequency, thereby reducing the LFRO effect in the frequencyresponse of the sound producing cell 600.

For example, in order to make d decreased, the membrane 110 may includeat least one spring connected between the subparts of membrane 110, suchthat the non-anchored edges of these subparts may be close to each otherin the direction Z during the operation of the sound producing cell 600.As shown in FIG. 14 , the membrane 110 may include at least one secondspring SPR2 and at least one third spring SPR3, the second spring SPR2may be directly connected between the first membrane subpart 112 and thethird membrane subpart 116 or directly connected between the firstmembrane subpart 112 and the fourth membrane subpart 118, and the thirdspring SPR3 may be directly connected between the second membranesubpart 114 and the third membrane subpart 116 or between the secondmembrane subpart 114 and the fourth membrane subpart 118. In FIG. 14 ,the membrane 110 may include two second springs SPR2 and two thirdsprings SPR3, two second springs SPR2 may be respectively connectedbetween the first membrane subpart 112 and the third membrane subpart116 and between the first membrane subpart 112 and the fourth membranesubpart 118, and two third springs SPR3 may be respectively connectedbetween the second membrane subpart 114 and the third membrane subpart116 and between the second membrane subpart 114 and the fourth membranesubpart 118, but not limited thereto. Note that the second spring SPR2and the third spring SPR3 are formed because of the slits SL (e.g., theslits SL other than the first slit SL1, the second slits SL2 and thethird slits SL3).

In addition, in one spring shown in FIG. 14 , the connecting directionfrom this spring to one subpart may be the same as the connectingdirection from this spring to another subpart, but not limited thereto.For example, in FIG. 14 , the spring may substantially be a U-shape, butnot limited thereto. For example, the U-shape of the spring may have agreat curvature, but not limited thereto. Due to this design, the sizeof the side opening between two subparts may be decreased (i.e., d isdecreased), so as to reduce the leakage of the air in the operation ofthe sound producing cell 600, thereby reducing the LFRO effect in thefrequency response of the sound producing cell 600.

For example, in order to make d decreased, the actuating layer 130 maybe disposed on the first membrane subpart 112, the second membranesubpart 114, the third membrane subpart 116 and the fourth membranesubpart 118. During the operation of the sound producing cell 600, theactuating layer 130 may actuate these subparts to move along thedirection Z, such that the non-anchored edges of these subparts may beclose to each other in the direction Z.

Moreover, in the region R3 shown in FIG. 15 , the sound producing cell600 may include a recess structure RS outside the membrane 110, whereinthe recess structure RS may be directly connected to a slit segment SLsin the corner region CR of the membrane 110, and the recess structure RSmay have a curved pattern (e.g., the recess structure RS may have apattern with a half circular arc). For example, in FIG. 15 , the slitsegment SLs may be connected between the end of the second slit SL2situated in the corner region CR and the recess structure RS, and theslit segment SLs may have a straight pattern, but not limited thereto.The existence of the curved recess structure RS connected to the slitsegment SLs situating in the corner region CR may enhance the successrate of the manufacturing process of the sound producing cell 600,thereby increasing the yield rate of the sound producing cell 600.

Referring to FIG. 16 , FIG. 16 is a schematic diagram of a top viewillustrating a sound producing cell according to a seventh embodiment ofthe present invention. As shown in FIG. 16 , a difference between thisembodiment and the sixth embodiment is the design of the spring. In thesound producing cell 700 shown in FIG. 16 , the fifth slits SL5including a hook-shaped curved pattern and a straight pattern may beindividually connected to the first slit SL1, the second slit SL2 or thethird slit SL3, and the second springs SPR2 and the third springs SPR3may be formed because of the first slit SL1, the second slits SL2, thethird slits SL3 and the fifth slits SL5, but not limited thereto.Furthermore, in FIG. 16 , the spring may substantially be a V-shape, butnot limited thereto.

Referring to FIG. 17 , FIG. 17 is a schematic diagram of a top viewillustrating a sound producing cell according to an eighth embodiment ofthe present invention. As shown in FIG. 17 , a difference between thisembodiment and the sixth embodiment is that the slits SL of the membrane110 of the sound producing cell 800 further includes at least one sideslit SLi formed on the third membrane subpart 116 and/or the fourthmembrane subpart 118.

Due to the existence of the side slits SLi, the structural strengths ofthe third membrane subpart 116 and the fourth membrane subpart 118 maybe weakened, such that the second spring SPR2 and the third spring SPR3may pull the third membrane subpart 116 and the fourth membrane subpart118 to make their the non-anchored edges be closer to the non-anchorededges of the first membrane subpart 112 and the second membrane subpart114 in the direction Z during the operation of the sound producing cell800.

On the other hand, compared with the structure which the side slit SLidoes not exist, the membrane 110 of this embodiment may form a pluralitysmaller openings replacing one original greater opening between twonon-anchored edges of the subparts during the operation of the soundproducing cell 800, wherein at least one smaller openings may be formedbetween two non-anchored edges, and at least one smaller opening may beformed by side slit(s) SLi. Namely, d of the original greater opening ischanged to a plurality of d′ of the smaller openings, and d′ is smallerthan d. For example, according to above formula, assuming that oneoriginal greater opening is replaced by three smaller openings and d ofthe original greater opening is three times greater than d′ of thesmaller opening, the acoustic resistance of three smaller openings isnine times greater than the acoustic resistance of the original greateropening. Thus, the acoustic resistance for low frequency may beincreased by this design.

As shown in FIG. 17 , the second spring SPR2 may be formed because ofthe first slit SL1, the second slit SL2, the fifth slit SL5 and the sideslit(s) SLi, and the third spring SPR3 may be formed because of thefirst slit SL1, the third slit SL3, the fifth slit SL5 and the sideslit(s) SLi, but not limited thereto.

In some embodiments, as shown in FIG. 17 , the actuating layer 130 maybe disposed on the first membrane subpart 112 and the second membranesubpart 114, and the actuating layer 130 may be not disposed on thethird membrane subpart 116 and the fourth membrane subpart 118 (i.e., noactuating layer is disposed on the third membrane subpart 116 and thefourth membrane subpart 118), but not limited thereto.

Moreover, in FIG. 17 , the membrane 110 may optionally include a firstspring SPR1 directly connected between the first membrane subpart 112and the second membrane subpart 114. For example, the first spring SPR1shown in FIG. 17 may be formed because of two first slits SL1 and twofifth slits SL5, but not limited thereto.

Referring to FIG. 18 and FIG. 19 , FIG. 18 is a schematic diagram of atop view illustrating a sound producing cell according to a ninthembodiment of the present invention, and FIG. 19 is a schematic diagramof a side view illustrating the sound producing cell according to theninth embodiment of the present invention, wherein FIG. 18 and FIG. 19only show the first membrane subpart 112, and the design of the secondmembrane subpart 114 may be similar to the design of the first membranesubpart 112. As shown in FIG. 18 , a difference between this embodimentand the first embodiment is the design of the anchored edge of thesubpart of the membrane 110. In the sound producing cell 900 of thisembodiment, the anchored edge of the subpart of the membrane 110 ispartially anchored, such that the anchored edge includes at least oneanchored part and at least one non-anchored part, wherein the anchoredpart of the anchored edge is anchored, and the non-anchored part of theanchored edge is non-anchored. For example, in FIG. 18 , the firstanchored edge 112 a of the first membrane subpart 112 which is partiallyanchored may include two anchored parts AP and one non-anchored part NPbetween two anchored parts AP, but not limited thereto. The non-anchoredpart NP of the first anchored edge 112 a may move toward the direction Zwhen the sound producing cell 900 is operated (i.e., the first membranesubpart 112 is actuated), so as to enhance the deformation of themembrane 110, thereby increasing the SPL of the acoustic wave producedby the sound producing cell 900.

In order to make the anchored edge have the anchored part(s) AP and thenon-anchored part(s) NP, the slits SL of the membrane 110 may include atleast one inner slit. In this embodiment, the first membrane subpart 112may have at least one first inner slit SLn1 and at least one secondinner slit SLn2, wherein the non-anchored part NP of the first anchorededge 112 a may be defined by the first inner slit SLn1, and the secondinner slit SLn2 is connected to the first inner slit SLn1, so as to makethe first anchored edge 112 a have the anchored part(s) AP and thenon-anchored part(s) NP. Namely, the first inner slit SLn1 may beparallel to the first anchored edge 112 a and between the first membranesubpart 112 and the anchor structure 120, and the second inner slit SLn2may be not parallel to the first anchored edge 112 a. For example, inFIG. 18 , the first membrane subpart 112 may have one first slit SL1 andtwo second slits SL2, and the second inner slit SLn2 may be a straightslit perpendicular to the first anchored edge 112 a, but not limitedthereto. For example, the second inner slit SLn2 may extend from thefirst anchored edge 112 a toward the first slit SL1, and the secondinner slit SLn2 may not be connected to the first slit SL1.

The first inner slit SLn1 defining the non-anchored part NP of the firstanchored edge 112 a may be connected between two slits SL. For example,in FIG. 18 , the first inner slit SLn1 may be connected between twosecond inner slits SLn2, such that the anchored part AP and thenon-anchored part NP of the first anchored edge 112 a may be divided bythe second inner slit SLn2, but not limited thereto.

Optionally, in FIG. 18 , the first inner slit SLn1 and the second innerslit SLn2 may be separated from the first slit SL1, the second slit SL2and the third slit SL3, but not limited thereto.

As shown in FIG. 18 , the first membrane subpart 112 may be divided intoa plurality of parts by the inner slits SL. For example, in FIG. 18 ,the first membrane subpart 112 may be divided into three parts 912 p 1,912 p 2 and 912 p 3, the part 912 p 1 and the part 912 p 3 may bebetween the second slit SL2 and the second inner slit SLn2, and the part912 p 2 may be between two second inner slits SLn2. For example, in FIG.18 , the part 912 p 1 and the part 912 p 3 may have the anchored part APof the first anchored edge 112 a, so as to be anchored by the anchorstructure 120. For example, in FIG. 18 , the part 912 p 2 may have thenon-anchored part NP of the first anchored edge 112 a, such that thepart 912 p 2 may move along the direction Z with greater displacement(compared with the parts 912 p 1 and 912 p 3) during the operation ofthe sound producing cell 900, thereby increasing the SPL of the acousticwave produced by the sound producing cell 900.

As shown in FIG. 18 , the actuating layer 130 may include three portionsrespectively disposed on three parts 912 p 1, 912 p 2 and 912 p 3 of thefirst membrane subpart 112, so as to actuate the first membrane subpart112.

In FIG. 19 showing the side view of the sound producing cell 900 duringits operation, the part 912 p 2 may move along the direction Z withgreater displacement (compared with the parts 912 p 1 and 912 p 3)during the operation of the sound producing cell 900, and thenon-anchored part NP of the first anchored edge 112 a may be higher thanthe anchored part AP in the direction Z.

Referring to FIG. 20 , FIG. 20 is a schematic diagram of a top viewillustrating a sound producing cell according to a tenth embodiment ofthe present invention. As shown in FIG. 20 , a difference between thisembodiment and the ninth embodiment is the design of the anchored edgeof the subpart of the membrane 110. In the sound producing cell 900′shown in FIG. 20 , the first anchored edge 112 a of the first membranesubpart 112 may include two non-anchored parts NP and one anchored partAP between two non-anchored parts NP, but not limited thereto. In FIG.20 , the first membrane subpart 112 may have two first inner slits SLn1and two second inner slits SLn2, and the first inner slit SLn1 may beconnected between the second inner slit SLn2 and the second slit SL2,but not limited thereto.

In FIG. 20 , the part 912 p 2 may have the anchored part AP of the firstanchored edge 112 a, so as to be anchored by the anchor structure 120.In FIG. 20 , the part 912 p 1 and the part 912 p 3 may have thenon-anchored part NP of the first anchored edge 112 a, such that thepart 912 p 1 and the part 912 p 3 may move along the direction Z withgreater displacement (compared with the part 912 p 2) during theoperation of the sound producing cell 900′, thereby increasing the SPLof the acoustic wave produced by the sound producing cell 900′.

In summary, according to the design of the sound producing cell of thepresent invention, the sound producing cell may achieve higher resonantfrequency, larger SPL, high yield rate and/or low air leakage.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. A sound producing cell, comprising: a membrane,comprising a first membrane subpart and a second membrane subpart,wherein the first membrane subpart and the second membrane subpart areopposite to each other; and an actuating layer, disposed on the firstmembrane subpart and the second membrane subpart; wherein the firstmembrane subpart comprises a first anchored edge which is fully orpartially anchored, and edges of the first membrane subpart other thanthe first anchored edge are non-anchored; wherein the second membranesubpart comprises a second anchored edge which is fully or partiallyanchored, and edges of the second membrane subpart other than the secondanchored edge are non-anchored.
 2. The sound producing cell of claim 1,wherein a first ratio of the membrane is larger than 2, and the firstratio of the membrane is a ratio of a first length of a first side ofthe membrane to a second length of a second side of the membrane.
 3. Thesound producing cell of claim 1, wherein the membrane comprises: a firstslit formed between the first membrane subpart and the second membranesubpart, wherein a first non-anchored edge of the first membrane subpartis defined by the first slit, and the first non-anchored edge isopposite to the first anchored edge in a top view; and a second slit,wherein a second non-anchored edge of the first membrane subpart isdefined by the second slit, and the second non-anchored edge is adjacentto the first anchored edge.
 4. The sound producing cell of claim 3,wherein the first non-anchored edge of the first membrane subpart and athird non-anchored edge of the second membrane subpart are defined bythe first slit, and the third non-anchored edge of the second membranesubpart is opposite to the second anchored edge of the second membranesubpart in the top view.
 5. The sound producing cell of claim 1,comprising a recess structure disposed at a corner of the soundproducing cell, configured to disperse a stress applied on the recessstructure during a peel-off process.
 6. The sound producing cell ofclaim 5, wherein the membrane comprises a slit segment in a cornerregion, and the recess structure is directly connected to the slitsegment.
 7. The sound producing cell of claim 5, wherein the recessstructure has a curved pattern.
 8. The sound producing cell of claim 1,comprising four recess structures disposed at four corners of the soundproducing cell, configured to disperse stress applied on the recessstructure during a peel-off process.
 9. The sound producing cell ofclaim 1, wherein the membrane comprises a latch structure configured tolimit moving distances of the first membrane subpart and the secondmembrane subpart; wherein the moving distances are distances along anormal direction of a base where the sound producing cell is disposed.10. The sound producing cell of claim 9, wherein the latch structurecomprises a first latch component and a second latch component, thefirst latch component is a portion of the first membrane subpart, andthe second latch component is a portion of the second membrane subpart.11. The sound producing cell of claim 9, wherein the membrane furthercomprises: a first slit formed between the first membrane subpart andthe second membrane subpart; wherein at least a portion of the latchstructure is formed because of the first slit.
 12. The sound producingcell of claim 1, wherein the membrane comprises: a third membranesubpart, disposed by a first side of the sound producing cell betweenthe first membrane subpart and the second membrane subpart in a topview; wherein the third membrane subpart is configured to reduceacoustic leakage at the first side of the sound producing cell; whereinthe third membrane subpart comprises a third anchored edge which isanchored, and edges of the third membrane subpart other than the thirdanchored edge are non-anchored.
 13. The sound producing cell of claim12, wherein the membrane comprises: a fourth membrane subpart, disposedby a second side of the sound producing cell between the first membranesubpart and the second membrane subpart in the top view; wherein thefourth membrane subpart is configured to reduce acoustic leakage at thesecond side of the sound producing cell; wherein the fourth membranesubpart comprises a fourth anchored edge which is anchored, and edges ofthe fourth membrane subpart other than the fourth anchored edge arenon-anchored.
 14. The sound producing cell of claim 12, wherein themembrane comprises: a first slit, formed between the first membranesubpart and the second membrane subpart, wherein a first non-anchorededge of the first membrane subpart is defined by the first slit, and thefirst non-anchored edge is opposite to the first anchored edge; and asecond slit, formed between the first membrane subpart and the thirdmembrane subpart, wherein a second non-anchored edge of the firstmembrane subpart and a fourth non-anchored edge of the third membranesubpart are defined by the second slit, the second non-anchored edge ofthe first membrane subpart is adjacent to the first anchored edge of thefirst membrane subpart, and the fourth non-anchored edge of the thirdmembrane subpart is adjacent to the third anchored edge of the thirdmembrane subpart.
 15. The sound producing cell of claim 12, wherein themembrane further comprises: a spring directly connected between thefirst membrane subpart and the third membrane subpart.
 16. The soundproducing cell of claim 12, wherein at least one side slit formed on thethird membrane subpart; wherein no actuating layer is disposed on thethird membrane subpart.
 17. The sound producing cell of claim 1, whereinthe first anchored edge is partially anchored; wherein the firstanchored edge comprises at least one anchored part and at least onenon-anchored part, the at least one anchored part is anchored, and theat least one non-anchored part is non-anchored; wherein the at least onenon-anchored part of the first anchored edge moves toward a normaldirection of a base on which the sound producing cell is disposed whenthe first membrane subpart is actuated.
 18. The sound producing cell ofclaim 17, wherein the first membrane subpart has at least one firstinner slit and at least one second inner slit; wherein the at least onenon-anchored part of the first anchored edge is defined by the at leastone first inner slit; wherein the at least one second inner slit extendsfrom the first anchored edge toward a first slit; wherein the first slitis formed between the first membrane subpart and the second membranesubpart, and a non-anchored edge of the first membrane subpart isdefined by the first slit.
 19. The sound producing cell of claim 18,wherein the first membrane subpart comprises two second inner slitsextending from the first anchored edge toward the first slit; wherein aportion of the actuating layer is disposed between the two second innerslits.
 20. The sound producing cell of claim 18, wherein the at leastone anchored part and the at least one non-anchored part are dividedaccording to the at least one second inner slit.